Carla Cristina Maganhin

Effects of melatonin on histomorphology and on the expression of steroid receptors, VEGF, and PCNA in ovaries of pinealectomized female rats

OBJECTIVE To evaluate the effect of melatonin both on the ovaries of pinealectomized female rats through histomorphometric analysis and on steroid receptors, proliferating cell nuclear antigen (PCNA), and vascular endothelial growth factor (VEGF) expression. DESIGN Experimental study. SETTING Federal University of São Paulo, Brazil. ANIMAL(S) Forty female rats. INTERVENTION(S) Forty rats were divided equally into four groups: GI-vehicle without surgery; GII--surgery without removal of the pineal gland (sham); GIII--pinealectomized with vehicle; and GIV--pinealectomized with melatonin treatment. After treatment for 3 consecutive months, the animals were killed and their ovaries removed for analysis. MAIN OUTCOME MEASURE(S) Estrogen and progesterone receptors, histologic and immunohistochemical analysis. RESULT(S) The GIII samples presented signals of proliferation on ovarian surface epithelium and interstitial cells as well as high expressions of PCNA and VEGF in those structures compared with GI, GII, and GIV. Also, the levels of progesterone receptor (fmol/g) in ovaries of GIII (250.6 ± 32.4) were significantly lower than in those of GI (429.0 ± 23,8), GII (442.3 ± 30.2), and GIV (564.1 ± 78.7). The levels of progesterone in GIII were superior to those in GI, GII, and GIV. CONCLUSION(S) Our findings suggest that melatonin may attenuate proliferation in ovarian structures and increase the number of luteal bodies as well as the levels of progesterone receptor.

Evaluation of FAS and caspase-3 in the endometrial tissue of patients with idiopathic infertility and recurrent pregnancy loss

OBJECTIVE To investigate expression of BcL-2, FAS, FAS ligand (FASL) and cleaved caspase-3 in the endometrial tissue of women with idiopathic infertility (with two consecutive failed cycles of in vitro fertilization) and women with idiopathic recurrent pregnancy loss. The control group consisted of fertile women. STUDY DESIGN Endometrial tissue samples from fertile women (n=25), women with idiopathic infertility (n=25) and women with idiopathic recurrent pregnancy loss (n=25) were collected on the seventh or eighth postovulatory day of their menstrual cycles for evaluation. Expression of BcL-2, FAS, FASL and cleaved caspase-3 was assessed using immunohistochemical methods. RESULTS Expression of BcL-2 and FAS was significantly higher and lower, respectively, in the women with idiopathic infertility than in the other groups (p<0.01). Expression of cleaved caspase-3 was significantly lower in the women with idiopathic infertility than in the other groups (p<0.01). Expression of FASL was similar in all three groups. CONCLUSION Disturbances in endometrial apoptosis may be a contributing factor in patients with idiopathic infertility and recurrent pregnancy loss.

Effects of Pentoxifylline on TNF-Alpha and Lung Histopathology in HCl-Induced Lung Injury

OBJECTIVE To evaluate the effects of pentoxifylline on hydrochloric acid-induced lung lesions in rats subjected to mechanical ventilation. METHODS Twenty male, adult Wistar-EPM-1 rats were anesthetized and randomly grouped (n=5 animals per group) as follows: control-MV (mechanical ventilation, MV group); bilateral instillation of HCl (HCl group); bilateral instillation of HCl followed by pentoxifylline (50 mg/kg bw) infusion (HCl+PTX group) and pentoxifylline infusion followed by bilateral instillation of HCl (PTX+HCl group). At 20, 30, 90 and 180 min after treatments, the blood partial pressures of CO2 and O2 were measured. The animals were euthanized, and bronchoalveolar lavages were taken to determine the contents of total proteins, corticosterone and TNF-α. Samples of lung tissue were used for histomorphometric studies and determining the wet-to-dry (W/D) lung weight ratio. RESULTS In the MV group, rats had alveolar septal congestion, and, in the HCl group, a remarkable recruitment of neutrophils and macrophages into the alveoli was noticed; these events were reduced in the animals with PTX+HCl. The partial pressure of oxygen increased in PTX+HCl animals (121±5 mmHg) as compared with the HCl (62±6 mmHg) and HCl+PTX (67±3 mmHg) groups within 30 minutes. TNF-α levels in bronchoalveolar lavage were significantly higher in the HCl group (458±50 pg/mL), reduced in the HCl+PTX group (329±45 pg/mL) and lowest in the PTX+HCl group (229±41 pg/mL). The levels of corticosterone in bronchoalveolar lavage were significantly lower in the HCl (8±1.3 ng/mL) and HCl+PTX group (16±2 ng/mL) and were highest in the PTX+HCl (27±1.9 ng/mL). CONCLUSION Pretreatment with PTX improves oxygenation, reduces TNF-α concentration and increases the concentration of corticosterone in bronchoalveolar lavage upon lung lesion induced by HCl.

Rat pinealectomy: a modified direct visual approach

PURPOSE To report a new, direct visual approach for rat pinealectomy. METHODS Eighty adult female rats (Rattus norvegicus albinus EPM-1 strain) were weighted and anesthetized intraperitoneally with 15 mg/kg xylazine and 30 mg/kg ketamine. The animal was fastened to a dissection table, an incision was made in the skin and the subcutaneous tissue, bringing the lambda into view. The skullcap was opened with a dental drill, bringing the cerebral hemispheres and the superior sagittal sinus into view. The pineal gland, located under the venous sinus, was removed in a single piece using tweezers. Next, the bone fragment was returned to its place and the surgical layers were sutured. RESULTS This new technique is easy to be done, avoids bleedings and removes only the pineal gland without damage to the remaining encephalon. In addition it makes possible the achievement of a sham surgery, allowing the pineal gland to remain intact. CONCLUSION The proposed technique intends to facilitate studies aiming to better understanding the complexity and importance of the pineal gland on reproductive and other body systems.

Effects of metformin on the reproductive system of androgenized female rats

Metformin improved the glucose rate and the homeostasis model assessment-insulin resistance (HOMA-IR) index and caused partial reversion of ovaries and uterine morphology in female rats androgenized with testosterone.

Melatonina: modulador de morte celular

Apoptosis or programmed death is a biological phenomenon, which is essential for the development and maintenance of a cell population. In this process, senescent or damaged cells are eliminated after activation of a cell death program involving participation of pro-apoptotic molecules (Fas, Fas-L, Bax, caspases 2, 3, 6, 7, 8 and 9). Molecule activation causes typical morphological changes, such as cell shrinkage, loss of adhesion to the extracellular matrix and neighboring cells, chromatin condensation, DNA fragmentation and formation of apoptotic bodies. Anti-apoptotic molecules (Bcl-2, FLIP) block the emergence and evolution of these cell changes and prevent cell death. The balance between molecules pro and anti-apoptotic ensures tissue homeostasis. When apoptosis is out of control, it contributes to the emergence of several neoplastic, autoimmune and neurodegenerative diseases. Several inducing and inhibitors of apoptosis agents are recognized as potential weapons in the fight against diseases related to proliferation and cell death disorders among which stand out hormones. Melatonin has been reported as important anti-apoptotic agent in various tissues by reducing cell calcium uptake, modulating expression of anti-oxidants and decreasing pro-apoptotic protein, such as Bax. The knowledge of new agents capable to act on the course pf apoptosis is important and of great value for developing further therapies against many diseases. Thus, the objective of this review was to elucidate the main aspects of cell death by apoptosis and the role of melatonin in this process.

Immunohistochemical evaluation of proliferation, apoptosis and steroidogenic enzymes in the ovary of rats with polycystic ovary

OBJECTIVE to evaluate the immunohistochemical expression of proliferative, apoptotic and steroidogenic enzyme markers in the ovaries of rats with polycystic ovary syndrome (PCOS). METHODS twenty rats were divided into two groups: GCtrl - estrous phase, and PCOS - with polycystic ovaries. The GCtrl animals were subjected to a lighting period from 7 am to 7 pm, while the animals with PCOS group remained with continuous lighting for 60 days. Subsequently, the animals were anesthetized, the ovaries were removed and fixed in 10% formaldehyde, prior to paraffin embedding. Sections were stained using H.E. or subjected to immunohistochemical methods for the detection of Ki-67, cleaved caspase-3, CYP11A1, CYP17A1 and CYP19A1. The results were analyzed using Students t-test (p < 0,05). RESULTS morphological results showed evidence of interstitial cells originating from the inner theca cells of degenerating ovarian cysts in PCOS. Immunoexpression of Ki-67 was higher in the granulosa cells in GCtrl, and the theca interna cells in PCOS, while cleaved caspase-3 was higher in granulosa cells of ovarian cysts from PCOS and in the theca interna cells of GCtrl. Immunoreactivity of CYP11A1 in the theca interna, granulosa and interstitial cells was similar between the two groups, while CYP17A1 and CYP19A1 were higher in the granulosa and interstitial cells in the PCOS group. CONCLUSION the results indicate that the interstitial cells are derived from the theca interna and that enzymatic changes occur in the theca interna and interstitial cells in ovaries of rats with PCOS, responsible for the high levels of androgens and estradiol.

Histomorphometric Analysis and Markers of Endometrial Receptivity Embryonic Implantation in Women With Polycystic Ovary Syndrome During the Treatment With Progesterone

Literature data indicate that the infertility in women with polycystic ovary syndrome (PCOS) is not only attributed to anovulation but also to endometrial dysfunction. Endometrial biopsies were performed in the proliferative and secretory phases of women with normal cycle and in women with PCOS before and after oral treatment with micronized progesterone. After the treatment, the endometrium of the women with PCOS exhibited a lower number of glands and thicker luminal epithelium compared to the normal women in the secretory phase. In addition, the PCOS group exhibited reduced integrin and MECA-79 immunoexpression during the secretory phase. The expression of E-cadherin was higher in the PCOS and the expression of intercellular adhesion molecule 1 was lower in PCOS, during the secretory and proliferative phases, respectively. Also, there is a negative correlation with MECA-79 and integrin expression and body mass index. Conventional doses of progesterone may not be enough to correct the changes of endometrial histomorphology and the receptive markers of PCOS-bearing women. The obesity may be a factor that interferes with this response.

Morfologia das células intersticiais de ovários policísticos de ratas: um estudo experimental

PURPOSES: To evaluate the histomorphometry of ovarian interstitial cells, as well as the blood sex steroid concentrations of female rats with polycystic ovaries induced by continuous light. METHODS: Twenty female rats were divided into two groups: Control Group - in the estrous phase (CtrlG), and a group of rats with polycystic ovaries induced by continuous illumination (POG). CtrlG animals were maintained on a light period from 07:00 a.m. to 07:00 p.m., and POG animals with continuous illumination (400 Lux) for 60 days. After this period all animals were anesthetized and blood was collected for the determination of serum estradiol (E2), progesterone (P4), and testosterone (T), followed by removal of the ovaries that were fixed in 10% formalin and processed for paraffin embedding. Five-µm histological sections were stained with hematoxylin and eosin and used for histomorphometric analysis. Morphological analyses, cyst count, determination of concentration and of the nuclear volume of interstitial cells were performed with the aid of a light microscope adapted to a high resolution camera (AxioCam), whose images were transmitted to and analyzed by the computer using AxioVision Rel 4.8 software (Carl Zeiss). Data were analyzed statistically by the Students t-test (p CtrlG=73.2±6.5, p CtrlG=80.6±3.9, p POG=4.2±1.5, p CtrlG=63.6±16.5, p CtrlG=6.9±3.2, p<0.05) compared to CtrlG animals. CONCLUSION: The interstitial cells of the rat polycystic ovary probably originate from ovarian cysts due to the degeneration of granulosa cells and differentiation of the internal theca cells. The elevations of serum testosterone and estradiol were probably due to the significant increase in cell activity and in the area occupied by interstitial cells.

Assessing the benefits of rosiglitazone in women with polycystic ovary syndrome through its effects on insulin-like growth factor 1, insulin-like growth factor-binding protein-3 and insulin resistance: a pilot study

The physiopathology of insulin resistance in women with polycystic ovary syndrome (PCOS) is related to a disturbance in the function of the insulin receptor. In fact, the post-receptor defect associated with PCOS may be a critical factor that interferes with the recruitment of proteins for intracellular glucose transport. The conceivable end result is a compensatory increase in insulin (1). One possible option for correcting this insulin resistance is the use of drugs (such as metformin and glitazones) that may increase glucose intake in the tissue (1,2). However, there are studies showing that a few patients interrupted their metformin treatment due to a high incidence of gastrointestinal side effects, such as nausea or vomiting (2). Rosiglitazone binds to the peroxisome proliferator-activated receptor, which regulates the transcription of many genes, including the glucose transporter, and decreases insulin resistance (4); however, this drug may increase the risk of cardiovascular diseases, such as myocardial infarction. These effects are not reported in patients who have insulin resistance without diabetes (5). It is important to emphasize that endothelial damage is more pronounced in diabetic patients than in non-diabetic ones (6). Approximately 1% of IGF-1 circulates freely in the plasma; the remainder is transported by binding proteins. The efficacy of muscle IGF-1 depends on the expression and availability of a family of six types of binding proteins. In humans, the most important of these proteins is IGFBP-3 (>80%), which is responsible for the maintenance of the circulating IGF-1 levels, along with the ALS glycoprotein, which has great affinity for IGF-1 and -2 (7). The increase in insulin may affect IGF-1 actions. In fact, insulin decreases the production of IGFBP-3 in the liver. Therefore, the free levels of IGF-1 are elevated and may affect ovarian function and increase androgen production (8). The aim of this study was to evaluate the actions of rosiglitazone on IGF-1 and IGFBP-3 in women with PCOS.